wal2mongo

pig build pkg wal2mongo         # build DEB packages

pig repo add pgsql -u          # Add repo and update cache

wal_level = logical
max_replication_slots = 10

-- Create a logical replication slot
SELECT * FROM pg_create_logical_replication_slot('w2m_slot', 'wal2mongo');

-- Perform DML operations
CREATE TABLE books (id SERIAL PRIMARY KEY, title VARCHAR(100), author VARCHAR(100));
INSERT INTO books (id, title, author) VALUES (123, 'My Book', 'Author');

-- Peek at changes (MongoDB format)
SELECT * FROM pg_logical_slot_peek_changes('w2m_slot', NULL, NULL);
-- Output: db.books.insertOne( { id:123, title:"My Book", author:"Author" } )

-- Consume changes
SELECT * FROM pg_logical_slot_get_changes('w2m_slot', NULL, NULL);

-- Drop the slot
SELECT pg_drop_replication_slot('w2m_slot');

pg_recvlogical -d postgres --slot w2m_slot --create-slot -P wal2mongo
pg_recvlogical -d postgres --slot w2m_slot --start -f -

// Copy the output from pg_logical_slot_get_changes
db.books.insertOne( { id:123, title:"My Book", author:"Author" } )

mongo < changes.js